FEDX-5172: Detect build readiness from webdev stdout#67
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FEDX-5172: Detect build readiness from webdev stdout#67btr-rmconsole-2[bot] merged 3 commits intomasterfrom
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Switches WebdevServer from ProcessStartMode.inheritStdio to
ProcessStartMode.normal so that webdev stdout can be monitored.
Exposes a stdoutLines broadcast stream on WebdevServer; stderr
continues to be forwarded to the parent process.
ServeCommand listens to stdoutLines, forwarding each line to
stdout and watching for build_runner's completion signal
('Built with build_runner' / 'Failed to build with build_runner').
Once detected, it emits '[INFO] Succeeded after N seconds' on its
own line.
Also adds a test verifying the build-complete signal appears in
webdev stdout before the HTTP server becomes responsive.
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Closed
SDK constraint is now >=3.0.0 so there is no need to test against 2.19.6.
Both workflows default to 2.19.6 if sdk is not specified; explicitly pass stable to keep CI on Dart 3.
robbecker-wf
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QA +1 CI passes on Dart stable. Internal testing shows existing scripts work. |
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@Workiva/release-management-p |
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Problem
With Dart 3 and newer webdev/build_runner versions, a line that the build/serve process previously emitted — which consumers used to detect readiness — is no longer output. This broke scripts in consumer repos that monitor for a readiness signal in webdev_proxy's output.
Solution
build_runnerreliably emits one of the following lines to webdev's stdout when the initial build finishes, regardless of verbose mode:Built with build_runner/jit in Xs; wrote N outputs.Failed to build with build_runner/jit in Xs; wrote N outputs.This PR switches
WebdevServertoProcessStartMode.normalto capture webdev's stdout, watches that stream for the build-complete signal, then emits[INFO] Succeeded after N secondson its own line — preserving compatibility with existing consumer scripts already monitoring for that string.Changes
WebdevServerusesProcessStartMode.normaland exposes astdoutLinesbroadcast stream; stderr is forwarded to the parent process unchangedServeCommandlistens tostdoutLinesto forward webdev output to the user and waits for the build-complete pattern before emitting the readiness signaltest/webdev_ready_detection_test.dartwith two tests: one verifyingWebdevServer.stdoutLinesemits the build-complete signal before the HTTP server is responsive, and one verifyingServeCommandemits'Succeeded after'in its outputKnown tradeoff
ProcessStartMode.normalcauses webdev to detect a pipe rather than a TTY, changing its progress output from\r-based in-place rewrites to newline-separated lines. This is spammier for large projects during the initial build. Feedback welcome on whether this tradeoff is acceptable.Test plan
dart test test/webdev_ready_detection_test.dart— verifies the build-complete signal appears inWebdevServer.stdoutLinesand thatServeCommandemits'Succeeded after'dart test test/webdev_server_test.dart— existing serve test still passesdart pub global activate -sgit https://github.com/Workiva/webdev_proxy.git --git-ref dart3_detect_ready_deterministicin a consumer project and confirm[INFO] Succeeded after N secondsis emitted after the initial build